1、在做分享功能时需要把链接转换成二维码

// 1. 实例化二维码滤镜CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];// 2. 恢复滤镜的默认属性[filter setDefaults];// 3. 将字符串转换成NSDataNSData *data = [self.shareUrl dataUsingEncoding:NSUTF8StringEncoding];// 4. 通过KVO设置滤镜inputMessage数据[filter setValue:data forKey:@"inputMessage"];// 5. 获得滤镜输出的图像CIImage *outputImage = [filter outputImage];_imgView.image = [self createNonInterpolatedUIImageFormCIImage:outputImage withSize:200];//重绘二维码,使其显示清晰

2、处理重新生成image

/*** 根据CIImage生成指定大小的UIImage** @param image CIImage* @param size 图片宽度*/
- (UIImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)image withSize:(CGFloat) size
{CGRect extent = CGRectIntegral(image.extent);CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));// 1.创建bitmap;size_t width = CGRectGetWidth(extent) * scale;size_t height = CGRectGetHeight(extent) * scale;CGColorSpaceRef cs = CGColorSpaceCreateDeviceGray();CGContextRef bitmapRef = CGBitmapContextCreate(nil, width, height, 8, 0, cs, (CGBitmapInfo)kCGImageAlphaNone);CIContext *context = [CIContext contextWithOptions:nil];CGImageRef bitmapImage = [context createCGImage:image fromRect:extent];CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);CGContextScaleCTM(bitmapRef, scale, scale);CGContextDrawImage(bitmapRef, extent, bitmapImage);// 2.保存bitmap到图片CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);CGContextRelease(bitmapRef);CGImageRelease(bitmapImage);return [UIImage imageWithCGImage:scaledImage];
}